Bicycle frame



FIG. 1 is a perspective view showing my new design for a bicycle frame;

FIG. 2 is a side elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a front elevation view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

CLAIM The ornamental design for a bicycle frame, as shown and described. 